3/4 inch mdf with lots of bracing and seperate chambers for mid basses and tweeter.

Honduran Mahogany veneer and solid Mahogany top and front bottom. I'm also making a grill to fill in between solid panels with a sub baffle to bring the drivers flush with the grill frame.

I built the chamber for the midbasses .5 ft^3 when I first thought I would use th 850467, but I'm now thinking I would rather use the 850439 without the phase plug. the response above 4500 hz looks like it could create problems with a first order crossover.

I also still haven't pinned down a choice for the tweeter, so any suggestions are welcome.

My last set of diy speakers were Dynaudio 17W75 with Dynaudio Esotec dome tweeter. Time, cats, a toddler, and years of compensating for missing sub with EQ has taken its toll and its time to move these to my office computer.

I've been distracted from this project for 3 months with my Aleph 2+ s and work. The drivers should arive tomorrow. They have 3 coats of poly, but need more. I only hope the sound is half as deep and 3 dimensional as the wood grain. I settled for a Peerless tweeter for now. The 811815 had a nice off axis response, and they will get a lot of use as background music. I may upgrade later.

Now I need suggestions for crossover. I think I have enough reponse overlap for first order. I like first order for the minimum phase error. I'm using 850439 HDS 6.5 with out phase plug to avoid the climbing sensitvity beyond 1.2KHz.

Nice woodwork. take care so that they wont be to bassy. They look like they could have that ability (check so that tot box qts in the sealed box is approx 0,7 and divide the 12 inch at 100 hz) Put them on spikes or somtging like that.

When using first order electrically, i think you may want to pull the HDS basses down early or ,due to the risning sensitivity in mid range, otherwise they will interfere a lot with the tweeter. Maybe at 1kz or just lower. Then divide the tweeter at 3kz or so, io with at least an octave apart.

I chose the 850439 without the phase plug because of the rising sensitivity of the one with the plug. The driver without the plug looks pretty flat until about 3.2khz. I've also hear things about Peerless specs being less than acurrate. Is this true about this driver?

I don't recall the actual volume, but I do have qts around .72 for the subcabinet for HDS.

I orderd a pair of 811815 tweeters and they arrived damaged. They looked kinda crappy. (expecially compaired to my old Dynaudio Esotec domes). I haven't cut the holes yet, so If someone could suggest a better tweeter for under $75.00 each that would work with the woofers, please speak up. After all of the money and work in the rest of the system, I'm sure the cheesy little Peerless tweeter I bought is going to be something I regret for a long time. (not really, I'll put them in a pair of computer/office speakers)

These things have a 3 15/16" faceplate while most of the Vifa and ScanSpeak drivers have 4 1/8". Enlarging the rabit 3/32" would be a real bitch to do nicely.

The subwoofer on the side is going to crossover at 100 hz. It is now a BR, but if I seal the port it will have a sealed QTS of about .68 (nice option) I can borrow a few 4" test balls from a plumber friend and see if I perfer the tighter bass or the 21 hz F3.

Brian: I TOTALLY agree with your choice of the peerless 850439 mid-bass driver. I read a good article by Sieg Linkwitz of Linkwitz Labs about a year ago and he really thoroughly tested several tweeters and mid-bass units. I seem to remember he really liked the ScanSpeak 2905/9700 dome tweeter. for its very detailed and LOW non-linear distortion character.? Scan Speak is a little $ pricey, BUT,....There are always the Morel Tweeters(MDT 29, 30, 33 and the Seas revelator tweeters. I don't remember the efficiency of the Vifa T26 but what ever you choose, I would try to pick a tweeter thats roughly the same efficiency as the Peerless. Also take a look at where the Peerless is about 6 db down from it's on-axis response, and that would be my approx reccomendation for your X-over to get a somewhat predictable summing of both drivers to a flat response. When you think of it in terms of the mid-bass actually is producing almost 90 percent of ALL of the fundanentals(200 - 3200Hz) assuming that you will likely cross the Peerless over above 2500Hz, and the tweeter is really dealing almost exclusively with harmonics, it becomes somewhat less of a strain. I have a set of small bookshelves that use the 850122 Peerless crossed over to a peerless 850167 1' Peerless dome @ 3Khz and even the Peerless dome sounds fairly decent. I have heard that the 439 mid bass is fairly easy to cross. I'd be interested to find out what you decided and how it turned out?!!

Hi, Brian:
I got a bit curious about the Vifa D26 tweet as it had been a while since I had looked at the on-paper response. Personally, I like what's on paper, BUT just a note and a possible caution.
First, if the Vifa specs for resonance are accurate, then a definite advantage for the D26 would be it's clear ability to be crossed at 2K or just below. Looking at the paper response for the Peerless 439, it looks like some imp/phase stuff happening between 3 - 4Khz. Looking at the D26 response, it TOO gets a little funky between 3.5 - 4.2khz. In my admittedly limited experience, when ever I have tried a first order X and either driver's on-paper response showed a definite peak or dip within an octave of the X-over, the ultimate room response only made it worse. I think I would either X the 439 lower, or would even more likely pick a diffferent soft dome that was a bit smoother out to about 6 - 7K, IF you are going to use a relatively simple X-over, AND imo there is LOTS to say good about simple!
Good luck,

I orderd a pair of 811815 tweeters and they arrived damaged. They looked kinda crappy. (expecially compaired to my old Dynaudio Esotec domes). I haven't cut the holes yet, so If someone could suggest a better tweeter for under $75.00 each [/B]

Don't discount the Peerless tweeters. I use the shielded version of the tweeter you mentioned, and it's a steller performer. Testing it's IMD shows that the tweeter has quite high performance, especially considering its price. Peerless is the only one I know that uses the 3 15/16" flange instead of 4.08" like everyone else, but other tweeters that are good buys/good performers are:

I've attached an IMD test using 3 tones 1350Hz, 1500Hz, and 1650Hz for this tweeter. The worst case distortion is 1.77%. The tweeter output level is scaled for 90dB at 1 meter, for most crossovers, 90dB at 1.5kHz is way louder than you would ever listen.